Various attachments have been utilized in the past for automatically forming pleats, ruffles and shirrs in garments and other sewn materials. For example, prior art shirring equipment utilizes separately operated feed dogs at the sewing needle of the sewing machine, whereby feed dogs beneath the presser foot pull the bottom ply of material at a predetermined rate to the sewing needle, and another feed dog ahead of the presser foot pulls the bottom ply of material at a faster rate toward the sewing needle, whereby the bottom ply of material is gathered by the first feed dogs and then both the bottom and top plies of material which are pressed toward the second set of feed dogs by the presser foot are moved at a slower rate to the sewing needle. This results in progressive gathering of the bottom ply of material and attaching the bottom ply in its gathered condition to the relatively flat top ply of material. While this procedure has been successful in forming shirred structures, the operator of such equipment is somewhat handicapped during the operation of the sewing equipment in that the lower ply of material that is being gathered at the sewing needle is hidden by the upper ply of material, and the operator must stop the process from time to time in order to assure that the work product is being properly formed.
Other equipment has been utilized to form pleats and ruffles in the top ply of material fed to sewing machines. These prior art devices include a reciprocatable feed blade that works against a stripper blade in front of the sewing needle, with the upper ply of material extending over the stipper blade. The feed blade engages the upper ply of material and pushes it at a faster rate across the stripper blade toward the sewing needle, while the conventional feed dogs move the lower ply of material at a slower rate to the sewing machine. When this procedure is performed for each stitch of the sewing machine, it is considered as a "ruffling" process, and when this procedure is performed for every third or more stitches of the sewing machine it is considered to be a "pleating" process. Both ruffling and pleating substantially reduce the speed of operation of the sewing machine, for example from about 7000 r.p.m. to about 4000 r.p.m. for ruffling, and from about 7000 r.p.m. to about 3000 r.p.m. for pleating. Moreover, it is difficult to stop and start the ruffling and pleating functions in the middle of a sewing run with the prior art attachments, so that the operator cannot maintain high production of the work product when the ruffling or pleating procedures must be initiated or terminated during the sewing run on the work product.
Another example of prior art is the use of a rotatable feed wheel positioned in front of the sewing needle of a sewing machine with the feed wheel working against a stipper plate. The feed wheel runs substantially at the same effective speed as the feed dogs of the sewing machine for the purpose of feeding the upper ply of material positively to the sewing needle at the same rate of feed as the lower ply of material is fed by the feed dogs, so that no relative stretching or bunching of the two plies of material is experienced in the work product. The feed wheel is operated by the sewing machine motor at a speed which directly corresponds to the speed of operation of the feed dogs and the feed wheel constantly engages the upper ply of material.